Farmers in Co Carlow are taking legal advice in an effort to prevent RTÉ from fencing off an area surrounding the television transmitter at the summit of Mount Leinster.
An Bord Pleanála has granted permission for a 2.4m-high (7.8ft) fence around the RTÉ compound, overruling the objections of its own inspector, Carlow and Wexford county councils, An Taisce, local farmers and mountain climbers.
Jim Barron, one of 17 farmers who own the commonage rights to 1,800 acres of the mountainside, accused RTÉ of a "land-grab" and said "An Bord Pleanála has overturned a very sensible decision by the county councils, who understand the area."
However, an RTÉ spokesman said that "only about one acre" of its seven-acre site would be enclosed by the fence.
RTÉ was forced to remove a 2m-high chain-link fence enclosing four acres around the site in 2002 after failing to secure retention permission on appeal to An Bord Pleanála.
RTÉ claimed in submissions to the planning board that the fence is necessary "to ensure the safety of members of the public visiting the area, which is popular with hill-walkers". RTÉ also said the transmission mast "regularly gets iced up and large blocks of thawing ice can do damage to persons or property within and outside the compound".
However, the Mountaineering Council of Ireland told planners that "falling ice is not a real threat as RTÉ has had masts on four mountain summits for over 40 years without mishap".
Green Party deputy leader Mary White, a member of Carlow County Council, said "the summit of Mount Leinster will look like Colditz" and that the metal palisade-type fence will damage the "very special visual character of the area, which is one of Carlow's and Wexford's greatest amenities".
Last month planning board inspector Frank Cosgrove recommended that permission be refused and wrote that "because of the exposed character and prominent position of the site, the type of metal palisade fence proposed would cause an unacceptable degree of harm to the amenities of the area and would, therefore, be contrary to the proper planning and sustainable development of the area".
He described the proposed fence as "harsh and industrial in appearance and, without suitable screening, would not be appropriate in this remote and beautiful landscape".
He was overruled by the board, which said the "development would not seriously injure the amenities" and it accepted RTÉ's views about site security.
Permission for the fence was granted subject to, as yet unspecified, "development charges" being paid to both Carlow and Wexford county councils and a requirement that the fence "shall have a non-reflective galvanised finish".
The transmitter on Mount Leinster was built in the 1960s and is operated by RTÉNL, a wholly owned subsidiary of RTÉ. The company, which has its own board of directors, was established in 2002 and it purchased the assets and contracts of the transmission business.